July, '09] ENTOMOLOGICAL NEWS. 313 



Orbits, the space immediately contiguous to the eyes, some- 

 times indicated by structural characters, at other times in- 

 definite. 



Oral margin, the anterior edge of the oral cavity, being the 

 lower edge of the epistoma. 



Oral cavity, the cavity directly below the edge of the epis- 

 toma, covered over in front with an oblique posteriorly extend- 

 ing skin or membrane. 



Outer vertical bristles, the outer pair of 4 bristles, borne on 

 the vertex and nearest to the inner and upper corner of the 

 eyes ; erect or diverging. 



Palpi, the mouth feelers; in the Calypterae usually club 

 shaped and attached to the proboscis near its base. 



Paracephalon or paracephalic plates, the lateral segmented 

 portions of the occiput, separated by the metacephalon and the 

 epicephalon. Parafacials, see Gena. 



Parafrontals, see genovertical plates. 



Parafrontal occipital ridge or Epicephalon, a ridge-like 

 sclerite formed by what seems to be a continuation of para- 

 frontals over vertex on occiput and which bifurcates above the 

 great central foramen. 



Peristoma, see epistoma. 



Posterior orbit, that portion of the occiput bordering on the 

 occipital margin of the eye; usually bare and bounded on the 

 rear by a row of small bristles. 



Posterior orbit, cillia of. A row of bristles along the rear 

 border of the posterior orbit, in the Calypterae. 



Postvertical bristles, the most rearward pair of lesser ocel- 

 lar bristles, placed close together, one on each side of the 

 median line of the occiput, below the inner verticals and above 

 the occipitocentrals. 



Preocellar bristles, a small pair of bristles sometimes found 

 on the front below the anterior ocellus. 



Proboscis, the extensile mouth, usually more or less folded 

 up under the head when at rest. 



Ptilinal suture, see frontal suture. 



Transfrontals, a variable number of the frontal bristles 

 which are directed across the frontal vitta. 



